I would really love it if one of you nice people where to help me out.
Im no expert on everything but i have been digging around for information and studying many computer parts over the last 4 days and my build is in the similar price range to you. I also live in Australia (QLD) and the best places to buy are MSY, u-mart and pccasegear (located in melbourne). Anyway this is what I have come up with and just posted a thread so keep an eye on mine as well.
CPU: Intel Core i5 3570 ($212)
mobo: ASRock H77-PRO4-MVP ($98)
RAM: Corsair Vengeance CML8GX3M2A1600C9W8GB (2x4GB) DDR3 ($69)
GPU: MSI Radeon HD7850 Twin Frozr 2GB OC ($255)
Power Supply: Corsair HX650 ($129)
Case: CoolerMaster HAF 912 Advanced ($99)
CPU Cooler: CoolerMaster Hyper 212 EVO ($37)
SSD: Samsung 830 Series 128GB ($127)
HDD: Seagate Barracuda 1TB ($92)
OSS: Windows 7 64bit Home Premium ($92)
Total = $1210
This should be more than enough for playing your games listed but you wont be able to do any serious overclocking or SLI in the future.
Hope this helps!